Schizophrenia is a mental disorder that is classified under Axis I of the Diagnostic and
Statistical Manual of Mental Disorders – Forth Edition (DSM-IV). Symptoms of schizophrenia
emerge typically in late adolescents or early adulthood. According to the DSM-IV, a diagnosis of
schizophrenia may be made if two or more of the characteristic active-phase symptoms are
evident for a significant portion of time during a one-month period. These active-phase
symptoms are classified as either positive in excessive behaviours (such as delusions,
hallucinations, disorganized speech, grossly disorganized or catatonic behaviour) or negative in behaviour deficits (such as avolition, alogia, anhedonia, or flat effect). The duration of the
disturbances must be persistent for at least six months and must include at least one month of
active-phase symptoms (DSM-IV). As well, the DSM-IV states that the individual must
experience functioning below their level of achievement prior to onset in areas such as self-care,